Phosphoric acid industrial uses

Some of the H2SiFg so produced finds commercial outlets (p. 810), but it has been estimated that 500 000 tonnes of H2SiFe is discarded annually by the US phosphoric acid industry, equivalent to 1 million tonnes of fluorspar — enough to supply that nation s entire requirements for HF. Production figures and major uses are in the Panel. 

Let us evaluate the BAHLM system for the removal of cadmium from industrial wet-process phosphoric acid (WPA) (for details, see Ref. [7]) containing 50 ppm Cd ([Cd],J and 20 ppm Cu ( Cu]ini, and reducing Cd to a final concentration of 1 ppm ([Cd] ). We would also like to evaluate the BAHLM system for the selective separation of cadmium and copper from WPA. Using the known data presented in Table 6.7, the effective feed-side membrane area, (Sp), can be evaluated by equation ... 

Sulfuric acid is a very important commodity chemical, and indeed, a nation s sulfuric acid production is a good indicator of its industrial strength. World production in 2001 was 165 million tons, with an approximate value of US 8 billion. The major use (60% of total production worldwide) for sulfuric acid is in the "wet method" for the production of phosphoric acid, used for manufacture of phosphate fertilizers as well as trisodium phosphate for detergents. In this method, phosphate rock is used, and more than 100 million tonnes are processed annually. This raw material is shown below as fluorapatite, though the exact composition may vary. This is treated with 93% sulfuric acid to produce calcium sulfate, hydrogen fluoride (HF) and phosphoric acid. The HF is removed as hydrofluoric acid. The overall process can be represented as ... 

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